Rentals

All of the rentals came from one company called Laser Maze
http://www.lasermaze.com/index.html

Our main contact was a man named Stewart McAllen (281-288-6565)
He owns the company and was great to work with.

We rented :
an inflatable slide
a mechanical bull
inflatable ponies
texas tumbleweeds/human spheres
a dunking tank
The total for all of these was $2,450

I researched and talked to just about every company that provides inflatables in this area. Some of the companies were cheaper, but didn't seem to have as much experience or professionalism.
I have to say that Laser Maze was great. I can't think of anything negative to say about them. If the cost is too high, then I would consider eliminating some of the rentals or replacing them with a cheaper altenative. Laser Maze can get you pretty much anything you want.